Download Notes - Cort W. Rudolph, Ph.D.

Learning: Responding to Our Environment
} Learning is all about understanding various
responses to stimuli & their affects on long term
patterns of behavior.
} Core questions:
§ Where does learned behavior come from?
§ How do we “know” what to do in response to the
environment?
• Answers lie in some form of “change in behavior.”
• After “learning,” we can do something new that we
couldn’t do before.
© 2016 Cengage Learning.
Reflexes vs. Instincts vs. Learning
} Reflexes are fast, responses to
stimuli
§ Mediated by circuits in the spinal cord
and brainstem
§ Serve to promote your welfare.
} Simple, inflexible, not learned through
experience (i.e., are innate)
§ Disadvantages of being inflexible and not
very adaptable to change.
• E.g., goose bumps
Responding to Our Environment
© 2016 Cengage Learning.
Reflexes vs. Instincts vs. Learning
} Instincts are innate patterns of behavior
§ Elicited by environmental stimuli that do not require
learning.
§ Do not need to be learned/are inflexible.
} More complex than reflexes, and are mediated
by processing higher in the brain.
• E.g., Contagious yawning
§ Yawning in general => cooling the brain
§ Might be related to empathy -- synchronize the arousal
state of whole groups.
Responding to Our Environment
© 2016 Cengage Learning.
Reflexes vs. Instincts vs. Learning
} Learning is a relatively permanent change in
behavior (or the capacity for behavior) due to
experience.
§ The core of this definition is “change in behavior.”
§ After learning, we can do something new that we
couldn’t do before.
• Enormous adaptive advantage!
Responding to Our Environment
© 2016 Cengage Learning.
Learning vs. States
} Not all changes in behavior are due to learning.
§ E.g., maturation; brain damage
} Definition limits changes to those that result from
experience.
§ “Relatively permanent change”
§ Brief or unstable changes/states are not a result of
learning.
• e.g., mood; sickness
Responding to Our Environment
© 2016 Cengage Learning.
Nonassociative Learning
• Nonassociative learning
• Changes in the magnitude of responses to a single
stimulus – not the formation of connections between
stimuli.
• Two important types:
• Habituation reduced reactions to repeated
experiences.
• E.g., 1st night in a hotel vs. 2nd night
• Sensitization increases reactions to stimuli
following exposure to one strong stimulus.
• E.g., earthquakes
Responding to Our Environment
© 2016 Cengage Learning.
Associative Learning
} Occurs when we form connections among stimuli
and/or behaviors
§ Classical conditioning
§ Operant conditioning
Responding to Our Environment
© 2016 Cengage Learning.
Classical Conditioning
} This section covers:
§ Principles, phenomena, and applications of
classical conditioning
© 2016 Cengage Learning.
DROOL WARNING!
© 2016 Cengage Learning.
Classical Conditioning
} Pavlov distinguished stimuli and responses into
two forms + “neutral”
§ “Conditioned” = things that must be learned
§ “Unconditioned” = things that are reflexive/occur
without any learning.
• Conditioned stimulus (CS) refers to an environmental event
whose significance is learned.
• Unconditioned stimulus (UCS) has innate, built-in meaning to
the organism.
• Conditioned responses (CRs) are learned reactions
• Unconditioned responses (UCRs) don’t need to be learned;
they appear without prior experience with a stimulus.
© 2016 Cengage Learning.
Classical Conditioning
} Let’s imagine a scenario in which we are conditioning a
dog to salivate to the sound of a metronome:
§ Dogs salivate (UCR) when the see food (UCS)
§ During conditioning, the sound of the metronome (NS)
is followed by food (UCS), which produces salivation
(UCR).
} The repeated pairing of the sound and food forms the
association between NS & UCR (i.e., learning occurs).
§ After conditioning, the sound of the metronome (now a
CS) by itself is sufficient to produce salivation (now a
CR).
• Learning has occurred!
© 2016 Cengage Learning.
The Classical Conditioning Process –
Before Conditioning
Classical Conditioning
© 2016 Cengage Learning.
The Classical Conditioning Process –
During and After Conditioning
Classical Conditioning
© 2016 Cengage Learning.
Classical Conditioning Terms
Term
Abbreviation
Definition
Unconditionedstimulus
US
Astimulusthatnaturallyandreliablyevokesa
response
Unconditioned response
UR
Theresponsethatisnaturallyandreliably
elicited bytheunconditionedstimulus
Neutralstimulus
NS
Astimulusthatdoesnotinitiallyelicit the
unconditionedresponse
Conditionedstimulus
CS
Astimulusthatwasonceneutral but,through
associationwiththeUS,nowelicits aresponse
Conditionedresponse
CR
Afterconditioninghasoccurred, theresponse
thatiselicited bytheconditionedstimulus
Classical Conditioning
© 2016 Cengage Learning.
Contingency and Contiguity
} Acquisition refers to the development of a
conditioned response.
} Acquisition requires contiguity:
§ Close proximity in time between the conditioned
stimulus (CS) and the unconditioned stimulus
(UCS).
• Learning is typically most effective when the CS appears right
before the UCS.
Classical Conditioning
© 2016 Cengage Learning.
Contingency and Contiguity
} Acquisition also requires contingency
§ An association between the conditioned stimulus
(CS) and unconditioned stimulus (UCS).
• Learning about a consistent signal is easier than
learning about a signal that only occurs some of the
time.
§ When contingency is high, the CS reliably predicts the
appearance of the UCS
Classical Conditioning
© 2016 Cengage Learning.
Contingency and Contiguity
CS = Ringing Bell; UCS = Steak
Classical Conditioning
© 2016 Cengage Learning.
Stimulus Generalization and Discrimination
§ Stimulus
Generalization: Once
a CR is acquired, there
is a tendency to
respond to stimuli that
are similar to the CS.
§ Stimulus
Discrimination
eventually allows us to
make fine distinctions
between the
implications of stimuli.
Classical Conditioning
© 2016 Cengage Learning.
Extinction and Spontaneous Recovery
§
Conditioned responses will undergo extinction if the
association between the CS and the UCS is broken.
§ E.g., Continue to expose dog to the ticking of the
metronome without providing any food
• Dog will eventually stop salivating in response to the sound.
§
Extinction is not the same thing as forgetting (i.e., new
learning that overrides old learning).
§ Evidence for this from observed spontaneous recovery
• The reappearance of CRs following periods of rest between
sessions of extinction training.
Classical Conditioning
© 2016 Cengage Learning.
Operant Conditioning
} This section covers:
§ Principles, phenomena, and applications of operant
conditioning
© 2016 Cengage Learning.
Thorndike’s Law of Effect
} Behaviors followed by pleasant or helpful
outcomes would be more likely to occur in the
future
} Behaviors followed by unpleasant or harmful
outcomes would be less likely to occur.
Operant Conditioning
© 2016 Cengage Learning.
Thorndike’s Law of Effect
} Based on observations
off of cats’ behavior in a
puzzle box he had
constructed.
§ To escape required a
complete sequence of
behaviors.
§ Through trial-and-error
learning, cat would
generally escape faster
on successive trials.
Operant Conditioning
© 2016 Cengage Learning.
Skinner and Behaviorism
} B.F. Skinner introduced the term operant
conditioning (OC) to the study of the law of
effect.
} In CC the organism does not actively choose to
operate on the environment to produce some
consequence
§ i.e., The response is forced from the animal.
§ Skinner referred to classically conditioned behavior
as respondent behavior.
Operant Conditioning
© 2016 Cengage Learning.
Skinner & Behaviorism
} In OC the organism
makes a choice to
respond to its
environment
§ KEY: In OC learning,
behavior operates on the
environment to produce
some consequence.
Operant Conditioning
© 2016 Cengage Learning.
Consequences of Conditioning
} In OC learning occurs via various
consequences of behaviors.
§ Consequences must be highly salient (very
desirable or very unpleasant) to be effective.
• Important: some types of consequences increase
behaviors and some types decrease behaviors.
Operant Conditioning
© 2016 Cengage Learning.
Consequences of Conditioning
} Skinner divided consequences into four classes:
positive reinforcement, negative reinforcement,
positive punishment, and negative punishment.
§ Both types of reinforcement increase their
associated behaviors
§ Both types of punishment decrease associated
behaviors
} KEY: We all have our own unique set of effective
reinforcers and punishers!
§ i.e., The identity of a reinforcer or punisher is defined by its
effects on behavior -- not by an intrinsic quality of the consequence
itself!
Operant Conditioning
© 2016 Cengage Learning.
Consequences of Conditioning
} Add some element to one’s environment
(“positive”), or remove an element (“negative”)
} This can lead to an increase in the behavior
(“reinforcement”), or a decrease in the behavior
(“punishment”)
Add stimulus to
environment
Remove stimulus from environment
Make behavior
more frequent
Positive reinforcement
Negative reinforcement
Make behavior
less frequent
Positive punishment
Negative punishment
} People constantly get these confused!© 2016 Cengage Learning.
Operant Conditioning
Positive Reinforcement
• Positive reinforcement increases the frequency of
its associated behavior by providing a desired
outcome.
Operant Conditioning
© 2016 Cengage Learning.
Negative Reinforcement
• Negative reinforcement involves the use of unpleasant
consequences to increase the frequency of an associated
behavior.
• Behavior is strengthened through negative
reinforcement when the behavior results in the removal
or termination of something unpleasant.
• Many everyday behaviors are maintained by negative
reinforcement.
• We buckle up in our cars to turn off annoying beeps,
• Open umbrellas to avoid getting wet
• Scratch an insect bite to relieve the itch.
Operant Conditioning
© 2016 Cengage Learning.
Negative Reinforcement
Operant Conditioning
© 2016 Cengage Learning.
Positive Punishment
} Positive punishment refers to applying an
aversive consequence that reduces the
frequency of or eliminates a behavior.
§ This cat’s behavior (scratching the furniture) is
punished by adding an unpleasant outcome (a
squirt from a water bottle)
Operant Conditioning
© 2016 Cengage Learning.
Negative Punishment
} Negative Punishment: Removing a stimulus
from the environment to make a behaviror less
frequent.
§ E.g., Taking a privileges/objects away from people
is a form of negative punishment.
} Other notes about punishment:
§ Consequences have to matter to the person or
animal receiving them (i.e., significance).
§ Immediate punishment is much more effective than
delayed punishment (i.e., immediacy).
§ Effective punishment must follow uniform
application (i.e., consistency).
© 2016 Cengage Learning.
Operant Conditioning
A Bit of Review
Type of Learning Cognitive Process
Examples
Associative
Form new connections among
stimuli and behaviors
• Classical Conditioning
• Operant Conditioning
Nonassociative
Change the magnitude of
responses to a kind of stimulus
• Habituation
• Sensitization
Observational
Learning by watching the
actions and experience
of another
• Imitation
Operant Conditioning
© 2016 Cengage Learning.
A Bit of Review
Classical Conditioning
Operant Conditioning
Association between conditioned &
unconditioned stimuli
Association between behavior &
consequences
Organism responds to environment
Organism acts on environment
Behavior is reactive
Behavior is instrumental
Best with involuntary behaviors
Best with voluntary behaviors
Operant Conditioning
© 2016 Cengage Learning.
A Bit of Review
Add stimulus to
environment
Remove stimulus
from environment
Increase behavior
Positive reinforcement
Negative reinforcement
Decrease behavior
Positive punishment
Negative punishment
Operant Conditioning
© 2016 Cengage Learning.
Positive Reinforcement
A dog that begs is
given a treat; it will
learn to beg more often.
Operant Conditioning
© 2016 Cengage Learning.
Positive Punishment
A kitten that scratches
is scolded; it will learn
not to scratch.
Operant Conditioning
© 2016 Cengage Learning.
Negative Reinforcement
A woman hits the snooze
button on her alarm; she
will start hitting the snooze
button more often.
Operant Conditioning
© 2016 Cengage Learning.
Negative Punishment
A girl who breaks a rule
has to give up her phone
(removing privileges).
Operant Conditioning
© 2016 Cengage Learning.
Schedules of Reinforcement
} Continuous
§ Every time a behavior occurs
} Partial
§ Ratio or interval
§ Fixed or variable
Operant Conditioning
© 2016 Cengage Learning.
Schedules of Reinforcement
• A fixed ratio (FR) schedule requires that a
behavior occur a set number of times for each
reinforcer.
• Reinforcers in variable ratio (VR) schedules are
given after a fluctuating number of behaviors.
• In a fixed interval (FI) schedule, as set amount of
time must pass before reinforcement becomes
available following a response.
• In a variable interval (VI) schedule the time
interval is allowed to fluctuate around some
average amount over the course of a session.
Operant Conditioning
© 2016 Cengage Learning.
Effects of Reinforcement Schedules
} Variable Schedules > Fixed Schedules.
§ FI low rates of responding at the beginning of the
interval and accelerated responding at the end.
} Which is better?
§ VR reinforcement leads to rapid and consistent
increase in behavior.
§ FR and FI: Behavior tends to drop immediately
after a reward, and speed close to next reward.
§ VI reinforcement behavior is slow to increase, but
steady.
Operant Conditioning
© 2016 Cengage Learning.
Effects of Reinforcement Schedules
Operant Conditioning
© 2016 Cengage Learning.
Shaping
} What happens if you want to increase the
frequency of a behavior that rarely or never
occurs?
} Shaping via the method of successive
approximations
§ Begin by reinforcing spontaneous behaviors that
are somewhat similar to the target behavior we
want to train.
§ Use gradually more stringent requirements for
reinforcement until the exact behavior we want
occurs.
Operant Conditioning
© 2016 Cengage Learning.
Bandura’s Experiments
•
Some, but not all, learning occurs via reinforcement.
•
Bandura & Social Learning Theory.
•
•
i.e., learning via modeling others’ behavior (aka.
observational learning)
•
“Bobo Doll Experiments” Children watched films in
which a woman beat up the Bobo doll.
•
E.g., hit with a mallet, sat on it, threw in the air.
•
Child were then placed them in a room alone with the Bobo
doll and observed their behavior without their knowledge.
If the children imitated the characteristic behaviors of the
model, then learning had occurred.
Operant Conditioning
© 2016 Cengage Learning.
Bandura’s Experiments
Bobo Doll Video
© 2016 Cengage Learning.